Gear, motor-gear unit, vehicle and generator with a gear and force transmitting element

ABSTRACT

A gear has an input shaft and an output shaft, the gear includes the following elements: an outer wheel; an inner wheel which is positioned concentrically in relation to the outer wheel; a traction means extending between the outer wheel and the inner wheel; and a revolving transmitter which lifts the traction means from an outer periphery of the inner wheel and pushes the traction means onto an inner periphery of the outer wheel, the transmitter includes a first transmitter element and a second transmitter element provided on a rotatable transmitter carrier, wherein the first transmitter element and the second transmitter element are rotatable on the transmitter carrier and wherein each transmitter element is provided eccentrically from a rotation axis of the transmitter carrier, the first transmitter element includes a first disk, and the second transmitter element includes a second disk.

The present application relates to a gear having an input shaft and anoutput shaft. More particularly, the present application relates to amotor-gear unit with such a gear and to a motor vehicle with such amotor-gear unit. The present application also relates to an electricgenerator with a drive unit such as an internal combustion engine orsuch as a propeller for water or wind, further having a generator unitfor generating electricity and having a gear in accordance with theapplication.

The present application provides an improved gear, motor-gear unit,vehicle, generator with a gear, and force transmitting element.

The gear has an input shaft and an output shaft and also an outer wheeland an inner wheel which is positioned concentrically in relation to theouter wheel and often inside the outer wheel. There is also aring-shaped or cylindrical or elliptic traction provided that extendsbetween the outer wheel and the inner wheel. A revolving transmitterlifts or drags the traction means away from the outer periphery of theinner wheel and pushes it onto the inner periphery of the outer wheel.This is a simple and reliable setup for a gearbox which can provide highgear ratios.

There are many ways for connecting the input shaft and the output shaftto the gear. It is especially advantageous to connect the input shaft tothe transmitter and to connect the output shaft is to the inner wheel orto the outer wheel. The wheel which is not connected to the output shaftneeds then to be kept steady or connected with a housing of the gear.

Alternatively, one can also connect the input shaft with the outer wheelor the inner wheel, while the output shaft is connected to thetransmitter. The wheel which is not connected to the input shaft needsthen to be kept steady or connected with a housing of the gear. Thisarrangement needs to be carefully designed in order to avoidself-locking of the transmitter but this is especially useful forconverting high input torques from slow power sources into highrotational frequencies as often needed by electrical generators.

The traction means can be provided as a closed chain of rotatablyinterconnected links such as a bolt chain or a roller chain.

It is not only possible to provide the chain as a single chain nut alsoas a double or triple chain. One advantage of such a double chain ortriple chain is that the transmitter can be provided in an axial planethat is different from the axial planes of the inner wheel or outerwheel. Higher gear ratios can then be provided.

The gear can be provided as a one row gear design wherein the tractionmeans has one single radial section that is provided both for thecontact with the outer wheel and for the inner wheel. In the one rowgear design, the transmitter often contacts the traction means fromwithin the gap between the inner wheel and the outer wheel. Thetransmitter, the inner wheel, the outer wheel as well as the tractionmeans respectively the pressure means are located essentially in thesame axial plane which makes the design axially symmetric.

In an axially asymmetric two row gear design, the inner wheel and theouter wheel are often located in different axial planes, wherein thetransmitter is either located in the axial plane of the inner wheel orin the axial plane of the outer wheel. The traction means then extendsaxially between the axial planes of the inner wheel and the outer wheel,contacting both the inner wheel and the outer wheel at differentsections of their respective circumferences.

In a three row gear design, the two pairs of an inner wheel and an outerwheel are often located in different axial planes, wherein thetransmitter is located in a third axial plane between the two pairs ofan inner wheel and an outer wheel. One can also think of a three rowgear design with two inner wheels and one outer wheelor—alternatively—also with two outer wheels and one inner wheel. In afurther alternative, it is also possible to provide a double rowtransmitter with two transmitter sections, wherein each transmittersection is provided in an axial plane which is different from the axialplane of the inner wheel. The traction means then extends axiallybetween the axial planes of the outer wheels and the inner wheel,contacting both the inner wheel and the outer wheels at differentsections of their respective circumferences.

It is also possible to provide a axially symmetric three row gear designwith two outer wheels and one inner wheel, that are located in differentaxial planes, wherein the transmitter is located in the axial plane ofthe inner wheel. It is then also possible to provide a double rowtransmitter with two transmitter sections, wherein each transmittersection is provided in the axial plane of each outer wheel. The tractionmeans then extends axially between the axial planes of the inner wheelsand the outer wheel, contacting both the inner wheels and the outerwheel at different sections of their respective circumferences.

The traction means may also comprise at least one continuous elliptictraction element that can also be a deformable circular ring orcylinder. Such a traction means is easy to manufacture, especially ifthe traction element is provided in the form of a flexible belt,possibly with teeth. Such a traction element is often made from plasticor rubber which provided on a metal meshing or a woven or non-wovenfabric.

In a very advantageous form, the traction element comprises a thin andflexible spline element, that is possibly provided with teeth and it canalso be made from plastic. The flexible spline element may comprise amultitude of pins that stand proud of or protrude from at least oneaxial surface of the spline element and that are coaxially arranged withthe flexible spline element. With such a traction element, extremelyhigh gear ratios can be achieved because the difference between thediameter of the outer wheel and the diameter of the inner wheel can bemade almost as small as the diameter of the pins.

The transmitter or the transmitters may be positioned on a rotatabletransmitter carrier by mounting them concentrically in relation to theouter wheel and the inner wheel. As said before, the transmitter carrieris preferably connected to the input shaft or to the output shaft forachieving high transmission ratios.

The transmitters can be each mounted on a shaft such that they are ableto rotate while the shafts are provided on the transmitter carrier.Alternatively, the transmitter may be fixed to the transmitter carrier,wherein the traction means comprises a multitude of rotatable contactelements such as rollers on chain bolts.

It also possible to provide the transmitters eccentrically from therotation axis of the transmitter carrier such that the rotation axis ofthe transmitter is positioned off the rotation axis of the transmittercarrier. This provides for new shapes of the outer surface of thetransmitters that are easy to manufacture.

Alternatively, the rotation axis of the transmitter may essentiallycoincide with the rotation axis of the transmitter carrier, wherein acontact surface of the transmitter facing towards the traction means isprovided with an essentially elliptic shape. Providing an essentiallyelliptic shape includes that a non-circular flat surface is providedwhich is round such that a bearing or a number of balls can be arrangedbetween the contact surface and the traction means.

In one possible use of the gear, an electric motor is provided, a rotorof the electric motor being connected to the input shaft of the gear.For lightweight vehicles, often a DC brushless motor with a radial gapis provided, but other types of motors and also internal combustionengines apply as well, as described below with the embodiments. The DCbrushless motor is easy to provide with the gear of the applicationbecause the gear housing can be the motor housing at the same time.

A vehicle, in particular a two- or three-wheeled vehicle, can beequipped with such a motor-gear unit, wherein at least one driven wheelof the vehicle is connected to the output shaft of the gear.

The gear may also be used for an electric generator with a drive unitsuch as an internal combustion engine or a propeller for water or windand with a generator unit for generating electricity. An input shaft ofthe gear is then connected to the drive unit and an output shaft of thegear being connected to an input shaft of the generator.

An advantageous transmitter assembly for contacting a traction means ina gear comprises one or more first transmitter elements and one or morea second transmitter elements that are provided on a rotatabletransmitter carrier that is mounted concentrically in relation to theouter wheel and the inner wheel and that is preferably being connectedto the input shaft or to the output shaft for achieving hightransmission ratios. The transmitter elements are each mounted on ashaft such that they can rotate on the transmitter carrier. The firsttransmitter element and the second transmitter element are providedeccentrically from the rotation axis of the transmitter carrier. Such anarrangement allows for new shapes of the transmitter which provides someextra degrees of freedom for the design of a gear.

It is then possible to tighten or tension the transmitter with the twotransmitter elements by shifting them with respect to each other. Aguide for shifting the first transmitter element with respect to thesecond transmitter element may therefore be provided, as well astransmitter adjustment slits with a guiding element, the guidingelements being either provided in carrier adjustment slits in thetransmitter carrier or the guiding elements being taken up by guidingslits in adjacent transmitter elements.

In an alternative form, the gear of the application is provided with aninput shaft and with an output shaft, wherein the at least one revolvingtransmitter pushes the pressure means away from the inner periphery ofthe outer wheel and pushes the pressure means onto the outer peripherythe inner wheel. This gear is very similar to the other alternativewhere the transmitter shifts the traction means away from the outerperiphery of the inner wheel into the inner periphery the outer wheel.Most of the design elements of the other gear can be used for the gearwith the pressure means, except that the pressure means needs to be ableto transmit compressive forces. This is why many chains with movablelinks cannot be used as a pressure means.

The application also provides a thin and flexible spline element for agear, the spline element comprising a multitude of pins that stand proudof or protrude from at least one axial surface of the spline element andthat are coaxially arranged with the flexible spline element. Themultitude of pins may also stand proud of both axial surfaces of thespline element. A flexible spline element in which the multitude of pinsare provided in a multitude of axial cylindrical orifices is easy tomanufacture. It has turned out that it is advantageous to make the pinsfrom steel, that is later hardened, and the spline element fromaluminium.

The embodiments of the application are explained in further detail withreference to the following figures, in which

FIG. 1 shows a front view of a motor-gear unit as disclosed in theapplication,

FIG. 2 shows a section through the motor-gear unit illustrated in FIG. 1along the line of intersection marked J-J in FIG. 1,

FIG. 3 shows a section through the motor-gear unit illustrated in FIG. 1along the line of intersection marked F-F in FIG. 1,

FIG. 4 shows a top view of the motor-gear unit illustrated in FIG. 1,

FIG. 5 shows a section through the motor-gear unit illustrated in FIG. 4along the line of intersection H-H,

FIG. 6 shows an angled front view of the motor-gear unit illustrated inFIG. 1,

FIG. 7 shows a view of the motor-gear unit illustrated in

FIG. 6 with the outer wheel cover removed,

FIG. 8 shows a further view of the motor-gear unit illustrated in FIG.6,

FIG. 9 shows a stator with an inner wheel carrier and inner wheel of themotor-gear unit as illustrated in FIG. 6,

FIG. 10 a top view of the stator with inner wheel carrier and innerwheel illustrated in FIG. 9 with the transmitter carrier in place,

FIG. 11 shows an angled rear view of a motor-gear unit as illustrated inFIG. 1,

FIG. 12 shows a view of the motor-gear unit illustrated in FIG. 11 withthe outer wheel removed,

FIG. 13 shows a further view of the motor-gear unit illustrated in FIG.11,

FIG. 14 shows a view of the motor-gear unit disclosed in FIG. 11 withthe outer wheel removed,

FIG. 15 shows a section through the motor-gear unit illustrated in FIG.14 along a plane of intersection M-M,

FIG. 16 shows an angled rear view of a further motor-gear unit asdisclosed in the application which is integrated in a vehicle frame,

FIG. 17 shows a view of a further motor-gear unit,

FIG. 18 shows a top view of a further motor-gear unit with a chainpinion fitted,

FIG. 19 to FIG. 22 illustrate the function of the harmonic chain geardisclosed in the invention,

FIG. 23 shows a harmonic chain gear as disclosed in one embodiment witha double chain,

FIG. 24 shows a view of a harmonic chain gear as disclosed in anembodiment with a triple chain,

FIG. 25 shows the harmonic chain gear illustrated in FIG. 24 along thecross-section marked F-F in FIG. 24,

FIG. 26 shows an exploded drawing of a further embodiment of a harmonicchain gear with a double chain,

FIG. 27 shows an exploded drawing of a further embodiment of a harmonicchain gear,

FIG. 28 shows a cut-out of a double roller chain,

FIG. 29 shows a partial-exploded drawing of a further embodiment of amotor-gear unit,

FIG. 30 shows an exploded drawing of the gear parts omitted in FIG. 29,

FIG. 31 shows a view of the motor-gear unit in FIG. 29,

FIG. 32 shows a section through the motor-gear unit in FIG. 29,

FIG. 33 shows a side view of the motor-gear unit in FIG. 29,

FIG. 34 shows a further section through the motor-gear unit in FIG. 29,

FIG. 35 shows a version of the previous embodiments with a pressuremeans,

FIG. 36 shows an exploded view of an embodiment of a harmonic chaindrive with a two-pin-row pin ring,

FIG. 37 shows a cross-section through the motor-gear unit of FIG. 36,

FIG. 38 shows an exploded view of an embodiment of a harmonic chaindrive with a two-pin-row pin ring and with a wire race bearing,

FIG. 39 shows an exploded view of an embodiment of a harmonic chaindrive with a two-pin-row pin ring and with and two oval dragger disks,

FIG. 40 shows a cross-section through the motor-gear unit as shown inFIG. 38 or FIG. 39,

FIG. 41 shows a cross-section through the motor-gear unit as shown inFIG. 36,

FIG. 42 shows a cross-section through the motor-gear unit as shown inFIG. 37,

FIG. 43 shows a cross-section through the motor-gear unit as shown inFIG. 38,

FIG. 44 shows a partial cross-section through the motor-gear unit asshown in FIG. 37,

FIG. 45 shows a side view of a pin ring,

FIG. 46 shows a cross section through an element of the pin ring,

FIG. 47 shows an exploded view of an embodiment of a harmonic chaindrive with a tooth belt

FIG. 48 shows a first cross-section through the harmonic chain drive ofFIG. 47, and

FIG. 49 shows a second cross-section through the harmonic chain drive ofFIG. 47.

FIGS. 1 to 15 show a first motor-gear unit 100 as disclosed in thisapplication.

As is shown most clearly in FIG. 2, which shows a cross-section throughthe motor-gear unit 100 disclosed in this application along the line ofintersection marked J-J in FIG. 1, said motor-gear unit 100 is dividedinto a cup-shaped housing 1, an inner wheel 6 which is provided in thiscase in one piece on an output shaft 11 mounted in the housing 1 suchthat it is able to rotate, and a roller chain 8 which is guided betweenthe housing 1 and the inner wheel 6 by a transmitter carrier 5 which ismounted in the housing 1 such that it is able to rotate.

As can clearly be seen in FIG. 1, the housing 1 has on its insideradially inward facing outer wheel toothing 2, while the inner wheel 6has radially outward facing inner wheel toothing 7. The roller chain 8is designed such that it engages in a form-fitting connection with boththe outer wheel toothing 2 and the inner wheel toothing 7.

The transmitter carrier 5 itself is most clearly illustrated in FIG. 3,which shows a further cross-section through the motor-gear unit 100along the line of intersection marked F-F in FIG. 1.

The first transmitter 3 and the second transmitter 4 which arepositioned between the outer wheel toothing 2 and the inner wheeltoothing 7 and rotate peripherally with the transmitter carrier 5, eachdrag a section of the roller chain 8 into the outer wheel toothing 2,the roller chain 8 being lifted off the first 3 and second transmitters4 by the inner wheel toothing.

The dragging or lifting of the roller chain 8 by the first 3 and secondtransmitters 4 is illustrated in FIG. 5 which shows a cross-sectionalong the line of intersection marked H-H in FIG. 4. For this purposethe first transmitter 3 and the second transmitter 4 each have a curvedsickle-shaped inner face 12 facing the inner wheel toothing 7 and aconvex outer face 13 which slides along on the roller chain 8.

The transmitter carrier 5 is designed as a cylindrical body which ismounted in the housing 1 on a front radial bearing 14 and a rear radialbearing 15, such that it is able to rotate about an axis of symmetry 10of the motor-gear unit 100. In this arrangement, the transmitter carrier5 is designed as one piece with the first 3 and second transmitters 4 asis illustrated most clearly in FIG. 3.

To simplify the assembly of the bearing of the transmitter carrier 5,the housing 1 is made of two parts: a cup-shaped front housing section16 and a cylindrical central housing section 17 which mate radially withone another. In this arrangement the front housing section 16 has aforwards extending bearing support 18 in which is positioned a frontoutput shaft bearing 19. Holes 20 in the region between the radial outerpart of the front housing section 16 and the bearing support 18 areshown most clearly in FIG. 6. A total of 12 such holes 20 is provided.They are sealed with transparent plastic panels (not illustrated)against oil leakage. These transparent panels provide a view of the oillevel in the housing and can be used to monitor the operation of themotor-gear unit 100.

The side of the housing 1 axially opposite the front housing section 16is closed by a cup-shaped rear housing section 9 which has a receivingopening 28 for a rear output shaft bearing 26 in which the output shaft11 is mounted such that it is able to rotate.

A disc-shaped stator plate 50 is clamped in an axially centred positionbetween the rear housing section 9 and the central housing section 17,where it is screwed to the rear housing section 9 with fixing bolts 51such that it is unable to rotate. The stator plate 50 has around itsperiphery a plurality of armatures 22 which lie opposite the innercasing surface of the transmitter carrier 5. In this arrangement thestators/armatures 22 are surrounded by coil windings (not shown in thisview) through which an electrical current flows when the motor-gear unit1 is in operation. In addition, several intermediate circuit annularcapacitors 52 with capacitor connectors 54 are provided as energyaccumulators for the inverter components 53 which are also provided onthe stator plate 50. Cooling bodies 55 extending between the invertercomponents 53 and the inner wall of the rear housing section 9 areresponsible for heat dissipation. In this arrangement the rear housingsection 9 is provided with cooling fins which are shown most clearly inFIG. 4.

The stator plate 50 is provided with electrical power via supply cables56 which run out through the rear housing section 9.

Positioned on the inside or on the inner casing surface of thecylindrical transmitter carrier 5—and distributed around the peripheryof the transmitter carrier 5—is a plurality of permanent magnets 21.These permanent magnets 21 are shown most clearly in FIG. 3 whichillustrates a section through the motor-gear unit 100 shown in FIG. 1along the line of intersection F-F. The rear housing section 9 and othercomponents of the motor-gear unit 100 are removed in FIG. 3. In thisarrangement the permanent magnets 21 are designed as parts of the casingsurface of an imagined cylinder, such that they lie flush with the innercasing surface of the transmitter carrier 5. Due to the presence ofthese permanent magnets 21 the transmitter carrier becomes the rotor ofan electric motor.

Lying radially opposite the permanent magnets 21 is a number ofarmatures 22 which are shown most clearly in FIG. 9. The armatures 22are positioned radially around the inside of the cylindrical casing ofthe inner wheel 6, such that they are able to rotate about the axis ofsymmetry 10 together with the inner wheel 6. In this arrangement thearmatures 22 are surrounded by a coil winding (not shown in this view)to which an electronic control unit (similarly not shown) applieselectrical power. This generates an alternating magnetic field whichinteracts with the permanent magnet 21.

As is shown particularly clearly in FIG. 3, the permanent magnets 21extend a little beyond the lower edge of the transmitter carrier 5.Fitted to the stator plate in the vicinity of the peripheral position ofthe permanent magnets 21 are sensors which allow the position of thetransmitter carrier to be identified. In this arrangement it is possibleto not only use the standard sensors such as Hall sensors, but alsoinexpensive optical sensors or simple induction coils in which thepermanent magnets 21 generate characteristic induction currents forchanges in the position of the transmitter carrier as they move past.

As shown particularly clearly in FIG. 2, the roller chain 8 has a numberof bolts 23 on which are positioned rollers 24 and plates 25 which,together with the bolts 23, form a plurality of chain links. In thisarrangement the external diameter of the rollers 24, the geometry of theouter wheel toothing 2 and the geometry of the inner wheel toothing 7are designed so as to create a chain drive between the housing 1 and theinner wheel 6.

In this arrangement a seal (not illustrated here) between the housing 1and the transmitter carrier 5 ensures that the roller chain 8 as well asthe sliding contact between the transmitters 3, 4 and the roller chain 8and the bearings 14, 15, 19 receives lubrication without oil reachingthe region of the stator 22, the stator plate 50 and the magnets 21.

To give a better understanding of the structure of the motor-gear unit100 FIGS. 6 to 15 show it in various stages of disassembly.

FIG. 6 shows an angled front view of the motor-gear unit 100 in itsfully assembled state. There is a clear view through the viewing panelsin the holes 20 of the manner in which the gear unit complete with outerwheel toothing 2, roller chain 8, inner wheel toothing 7 and the twotransmitters 3, 4 operates.

FIG. 7 shows a view of the motor-gear unit disclosed in FIG. 6 with thefront housing section 16 removed. The inner wheel 6 with the inner wheeltoothing 6 is clearly visible. The oil seal on the transmitter carrier 5in the region between the two transmitters 4, 5 has been removed in FIG.7 giving a view of the armature stampings of the stators 22.

FIG. 8 shows a view of the motor-gear unit 100 illustrated in FIG. 6with the stator plate 50 removed. The stators 22, which are stillvisible in FIG. 7, are therefore no longer visible in FIG. 8. As aresult, the permanent magnets 21 are clearly visible on the inside ofthe transmitter carrier 5.

FIG. 9 shows the stator 22 removed in FIG. 8 with the inner wheel 6 andthe output shaft 11, and FIG. 10 shows a top view of the stator with theinner wheel 6 as illustrated in FIG. 9, with the transmitter carrier 5in place and the two bearings 14, 15 and the stator plate 50 and thecapacitor connectors 54.

FIG. 11 shows an angled rear view of the motor-gear unit illustrated inFIG. 1 but with the rear housing section 9 removed. The transmittercarrier 5 with the projecting permanent magnets 21, which pass flush bythe stator plate, is clearly visible. The stator 22 is visible betweenthe permanent magnets 21 and the stator plate 50. This stator 22 isshown particularly clearly in FIG. 12 in which the front housing section16, the central housing section 17 and the transmitter carrier 5 havealso been removed.

FIG. 13 shows a view of the motor-gear unit 100 as illustrated in FIG.11 with the central housing section 17 and stator plate 50 removed.

FIG. 14 shows another view of the motor-gear unit 100 in the stateillustrated in FIG. 10.

FIG. 15 shows a section through the motor-gear unit as illustrated inFIG. 14 along the line of intersection M-M. The transmitter carrier 5with the two transmitters 3, 4 is clearly visible. The spaces betweenthe transmitters 3, 4 are sealed against oil leakage with plasticinspection glass (not shown here).

When the motor-gear unit 100 illustrated in FIGS. 1 to 15 is inoperation the chain drive with the housing 1, the inner wheel 6 and theroller chain 8 is actuated as follows. An alternating voltage is appliedin an appropriate manner to the coil windings (not shown here) aroundthe armatures 22 so as to create an alternating electromagnetic fieldwhich cooperates with the permanent magnets 21. In this arrangement anelectronic control device (of which the inverter components and theintermediate circuit annular capacitors are shown here) ensures that thealternating electromagnetic field sets the transmitter carrier 5 inrotation about the axis of symmetry 10. The first 3 and secondtransmitters 4 move together with the transmitter carrier 5 in acircular direction about the axis of symmetry 10.

As is seen most clearly in FIG. 5, in this arrangement links in theroller chain 8 are pushed consecutively peripherally towards the outerwheel toothing 2. In the process, the subsequent chain strand in theperipheral direction of the transmitter carrier 5 pulls the inner wheelafter it. In these circumstances the difference in radius between theouter wheel toothing 2 and the inner wheel toothing 7 results in apredetermined transmission ratio.

In the above described embodiment, a gear unit is combined with anelectric motor. The gear unit, comprising the housing 1 with the outerwheel toothing 2, the inner wheel 6 with the inner wheel toothing 7 andwith the output shaft 11, the roller chain 8, the transmitter carrier 5with the first 3 and second transmitters 4 can also be used with anothertype of motor that is adapted to drive the transmitter carrier 5. It isin principle also possible to drive the output shaft 11 while securingeither the transmitter carrier 5 or the housing 1. The output torque canthen be tapped either from the housing 1 or from the transmitter carrier5.

FIG. 16 shows an angled top view of a further motor-gear unit 100 asdisclosed in this application. The motor-gear unit 100 in FIG. 16 issubstantially the same as the motor-gear unit 100 shown in FIGS. 1 to15. Identical parts are given the same reference numerals. In thisarrangement a first frame tube 30 and a second frame tube 3 are weldedto the periphery of the front housing section 16, forming a frame of atwo-wheeled vehicle (not illustrated here). The output shaft 11 drives arear wheel of the vehicle (not shown here).

FIG. 17 shows a view of a further motor-gear unit which hassubstantially the same parts as the motor-gear unit shown in theprevious figures. Identical parts are given the same reference numerals.

In this arrangement a trailing or driven wheel 33 intended to take atyre of a two-wheeled vehicle is screwed to the output shaft 11. Thetrailing wheel 33 is provided with a free-wheeling device or free-wheel57.

As is shown particularly clearly in FIG. 17, a first transverse link 34and a second transverse link 35 a) are fixed to the front housingsection 16.

FIG. 18 shows a further motor-gear unit 100 which is designed as a wheelhub motor of a vehicle not shown here in full. Parts which are the sameas those in the motor-gear unit 100 shown in FIGS. 1 to 17 have the samereference numerals or the same reference numerals followed by anapostrophe in the case of parts with the same function but a differentform.

In contrast to the preceding embodiments the output shaft 11′ is fixed.It is mounted on two square ends 65 in wishbone tubes of a vehicle (notillustrated here). A rear shaft nut 64 tightens the rear housing section9′ onto a shaft projection 66 on the output shaft 11′. On the oppositeside of the output shaft 11′, a front shaft nut 63 sets the play of thebearing 19′, 60 by means of which the front housing section 16′ and thecentral housing section 17′ are mounted such that they are able torotate on the output shaft 11′ or the rear housing section 9′.

In this arrangement the front housing section 16′ and the centralhousing section 17′ are each provided with a rim flange 62, therebyforming a rim upon which the tyre 61 is placed.

The tyre 61 is therefore driven via the front housing section 16′ andthe central housing section 17′ while the output shaft 11′ is fixed inthe wishbone tubes 64.

FIG. 19 to FIG. 22 illustrate the function of the harmonic chain geardisclosed in the application. In this arrangement links in the rollerchain 8 are dragged or lifted successively peripherally by the first 4and second transmitters 4 into the outer wheel toothing 2.

In this case, the front housing section 16 is fixed to the outer wheeltoothing 2. This is indicated by the letter “B” marked on the top of thefront housing section 16 which is fixed in FIGS. 19 to 22.

The transmitters 3, 4 revolve with the transmitter carrier 5 whichrotates clockwise. In FIG. 19 the second transmitter 4 stands at aposition of −35° (degrees), in FIG. 20 the second transmitter 4 standsat a position of 2° (degrees), in FIG. 21 the second transmitter 4stands at a position of +25° (degrees) and in FIG. 22 the secondtransmitter 4 stands at a position of +53° (degrees).

In the process the chain strand of the roller chain 8 following thesecond transmitter 4 in the peripheral direction of the transmittercarrier 5 pulls the inner wheel 6 with it. This is indicated by means ofthe letter “C” marked on the inner wheel 6 and the letter “A” marked onthe roller chain 8.

When the second transmitter 4 moves clockwise from a position of −35°(degrees) in FIG. 19 to a position of +53° (degrees) in FIG. 22, theinner wheel 6 moves by an angle of approx. 30° (degrees) anticlockwise.

In these circumstances the difference in radius between the outer wheeltoothing 2 and the inner wheel toothing 7 results in a predeterminedtransmission ratio of approx. 3:1.

In the application, output can be achieved in several manners. Firstly,the outer wheel 1 can be fixed as is the case in the embodimentsillustrated in FIGS. 1 to 17. Here output is via the inner wheel 6 whenthe electric motor is driving the transmitter carrier 5. Alternatively,the inner wheel 6 can be fixed as in the embodiment illustrated in FIG.18. In this case output is via the outer wheel 1 when the electric motoris driving the transmitter carrier 5.

Alternatively it is also conceivable for the inner wheel 6 to be drivenby the electric motor and to fix either the transmitter carrier 5 or theouter wheel 1. When the outer wheel 1 is fixed, output is via thetransmitter carrier 5. Conversely, if the transmitter carrier 5 isfixed, output is via the outer wheel 1. In these designs it is necessaryto pay particular attention to the friction characteristics in theregion of the roller chain 8 to avoid self-inhibiting.

Self-inhibiting or self-locking can be avoided by means of theappropriate design of the sliding surfaces of the roller chain 8, andalso by means of friction-reducing measures such as lubrication oradditional bearings in the transmitters 3, 4, for example.

Accordingly the electric motor can also drive the outer wheel 1 withoutput being either via the transmitter carrier 5 or the inner wheel 6,depending on whether the inner wheel 6 or the transmitter carrier 5 isfixed.

The roller chain 8 can be replaced by other traction or pressure means,for example by a toothed belt which can also be provided with teeth onboth sides. A similar design will be illustrated with respect to FIGS.47-49. Instead of a form-fit as in the embodiments, whereby teeth on thewheels engage in gaps in the roller chain, a form-fit with teeth in thetraction or pressure means engaging in gaps in the inner wheel or outerwheels is possible. Finally, it is also conceivable to use a frictionconnection between the corresponding wheels and the traction or pressuremeans.

FIG. 23 shows a cross-section F-F of a further motor-gear unit 100 whichis designed as a wheel hub motor of a vehicle (not illustrated in full).Parts which corresponds to parts in the previous FIGS. 1 to 22 have thesame reference numerals. The section is labelled F-F since theorientation of the cross-section is the same as in FIG. 3 in which thechain 8 is lifted off the inner wheel 6.

In comparison to FIG. 3, the transmitter carrier 5 is extended by acup-shaped region 79 on the side of the inner wheel 6.

Provided on the cup-shaped region 79 are two shafts 83, 84 which arepositioned parallel to the axis of symmetry 10. Two gear wheels 80, 81are mounted on ball bearings 85, 86 on the shafts 83, 84. The gearwheels 80, 81 correspond to the transmitters 3, 4 shown in FIG. 3. Thegear wheels 80, 81 are engaged in the inside of a second chain 82 of adouble chain 8′. The second chain 82 is indicated by means of a brokenline 90. The two shafts 83, 84 are positioned opposite one another inrelation to the axis of symmetry 10 and are the same distance from theaxis of symmetry 10. In the embodiment illustrated in FIG. 23 thisdistance is smaller than the radius of the inner wheel 6.

As described above, in operation the transmitter carrier 5 is set inrotation by forces acting on the permanent magnets 21. The outside of afirst chain 87 of the double chain 8′ is thus drawn into the outer wheeltoothing 2 by means of the gear wheels 80, 81. The inside of the firstchain 87 of the double chain 8′ is engaged with the inner wheel toothing7 and the inner wheel 6 and, thus, the output shaft 11 are thereforedriven in the manner previously shown in FIGS. 19 to 22.

The use of a double chain 8′ allows the gear wheels 80, 81 to rotate ina plane parallel to the inner wheel 6. Thus the optimum size can bechosen for the gear wheels 80, 81. Using larger gear wheels 80, 81increases the contact surface between the gear wheels 80, 81 and thechain 8′ and between the chain 8′ and the outer wheel toothing 2. Theforces occurring are thus more evenly distributed and the load on thechain 8′ and the outer wheel toothing 2 reduced. In addition, it ispossible to make the distance between the inner wheel toothing 7 and theouter wheel toothing 2 smaller. This means that it is possible toachieve higher speed-reduction at a given tooth size.

Instead of the gear wheels 80, 81 it is also possible to use rollerswhich push the inside of the second chain 82 outwards.

The rollers and, in particular, the gear wheels 80, 81 are able todeflect the forces which occur along the periphery of the chain 8′. Thisleads to lower friction losses when the chain 8′ is drawn into theexternal teeth 2.

FIGS. 24 and 35 show a further embodiment in which a triple chain 8″ isprovided in place of the double chain 8′ as shown in FIG. 23. Elementsalready shown in FIG. 23 are not reiterated. The sectional plane H′-H′shown in FIG. 24 is positioned parallel to the corresponding sectionalplane H-H shown in FIG. 4 and offset towards the output shaft 11.

A transmitter disc 90 is mounted on the output shaft 11 such that it isable to rotate freely. Provided in the transmitter disc 90 are twoshafts 91, 92 on each of which a gear wheel 93, 94 is positioned. Thegear wheels 93, 94 are located on opposing sides in relation to the axisof symmetry 10 and engage in a third chain 88 of the triple chain 8″from within. The transmitter disc 90 is cut out in the area of theshafts 91, 92 in such a manner that the region in which the triple chainis lifted off the inner wheel 6 remains free. In the centre of thetransmitter disc 90, a circular opening is left free around the outputshaft. Two outer regions 95, 96 of the transmitter disc 90 are locatedoutside the periphery of the inner wheel toothing 7 and are connectedrigidly to the transmitter carrier 5 by two fixings (not illustrated).The fixings pass through the space between the inner wheel 6 and theouter wheel toothing 2.

FIG. 25 shows a section along the line of intersection marked F-F inFIG. 24 which corresponds to the section shown in FIG. 23. As shown bestin FIG. 25, the gear wheels 93, 94 are positioned opposite gear wheels80, 81 which engage in the second chain 82 of the triple chain 8″ fromwithin. Like gear wheels 80, 81, gear wheels 93, 94 are also mounted onball bearings 97, 98. For reasons of clarity in FIG. 25 the second chain82 and the third chain 88 are indicated by means of broken lines andonly the uppermost and lowermmost chain bolts are drawn in full.

Due to the axially symmetrical arrangement of the triple chain 8″ inrelation to the inner wheel 6 shown in FIG. 25, the load on the triplechain 8″ is more uniform than for the double chain 8′ shown in FIG. 23.

The transmitter disc 90 can be supported by an additional bearing on theoutput shaft 11. Instead of a cup-shaped region 79 the transmittercarrier 5 can also be of another suitable shape. In addition, theembodiments shown in FIGS. 23 to 25 can also be combined with the otheroutput variants specified above. Further, it is possible to providetransmitters which are fixed to the transmitter carrier instead of thegear wheels or rollers. This results in a simpler design.

FIG. 26 shows an exploded drawing of a further embodiment of a harmonicchain gear. It is viewed from the side opposite the input. Parts locatedbehind the inner wheel 6 in direction x are not shown. As in FIG. 23,FIG. 26 also shows a double chain 8′ with a first chain 87 on the inputside and a second chain 82, the first chain 87 and the second chain 82being integrated into one integral double chain. The first chain 87 isalso called first chain row and the second chain 82 is also calledsecond chain row. Unlike in FIG. 23, a chain slide 100 for dragging thefirst chain 87 of the double chain 8′ into the outer wheel toothing 2 isprovided in the axial plane of the second chain 82. The outer wheelwhich contains the outer wheel toothing 2, comprises four parts, beingmade up of four identically shaped quarter rings 105, 106, 107, 108. Thelength of the double chain 8′ is dimensioned such that the double chain8′ lies adjacent to the periphery of the chain slide 100. An inner wheel6 is located in the plane of the input-side chain 87 of the double chain8′ and is designed as a ring with external toothing. A transmittercarrier 5 passes through the inside of the inner wheel 6.

The chain slide consists of four plates 3, 4, 101, 102 located in theplane of the chain 82. In the region of the plates 3, 4 the double chain8′ is lifted off the inner wheel 6. The plates 3, 4, 101, 102 thus serveas transmitters 3, 4, 101, 102 for transmitting the torque between thetoothing of the inner wheel 6 and the outer wheel toothing 2. The plates3, 4, 101, 102 of the chain slide 100 are screwed in position between around centring plate 104 and a disc-shaped slide chain holder 103. Thecentring plate 104 and the chain slide holder 103 thus form componentsof the transmitter carrier 5. Screw holes are provided in the quarterrings 105, 106, 107, 108 of the inner wheel 6, in the chain slide holder103, in the plates of the chain slide 100, in the centring plate 104 andin the front housing section 16 for assembly from the front. If input isto be via the outer wheel and output via the transmitter carrier 5,assembly is carried out as follows. The outer wheel is screwed to ahollow cylinder which is connected to a rotor of the drive motor. Theinner wheel 6 is screwed to a further hollow cylinder which is connectedto the stator 22. In addition, the chain slide holder 103, the chainslide 100 and the centring plate 104 are screwed to the output shaft 11by means of screw holes positioned one above the other.

In an alternative embodiment to FIG. 26 the chain slide of thetransmitter carrier can also be designed as one part and the inner wheelcan consist of a different number of parts. The transmitter carrier 5can also be designed such that rollers or gear wheels—as shown in FIG.23—are fitted to it which drag or lift the double chain 8′ into theouter wheel toothing 2.

Due to the use of a double chain 8′, the pressure force of thetransmitter 3, 4, 101, 102 does not act directly on the outer wheel 105,106, 107, 108. Any running noise can be compensated for by the doublechain 8′. In particular, the outer wheel can be made from a plurality ofparts and is thus easier to manufacture.

In the above described embodiment, a gear unit is often combined with anelectric motor. The gear unit comprising the double chain 8′, the chainslide 100, the outer wheel toothing 2, the inner wheel 6, and thetransmitter carrier 5 with the transmitters 3, 4, 101, 102 can becombined with any type of motor, engine or turbine. It is in principlepossible to drive the outer wheel 105, 106, 107, 108, the inner wheel 6or the transmitter carrier 5. If the outer wheel 105, 106, 107, 108 isdriven, one can then secure either the transmitter carrier 5 and tap theoutput torque from the inner wheel 6 or one secures the inner wheel 6and taps the output torque from the transmitter carrier 5. If the innerwheel 6 is driven, one can then secure either the transmitter carrier 5and tap the output torque from the outer wheel 105, 106, 107, 108, orone can secure the outer wheel 105, 106, 107, 108 and tap the outputtorque from the transmitter carrier 5. If the transmitter carrier 5 isdriven, one can then either secure the inner wheel 6 and tap the outputtorque from the outer wheel 105, 106, 107, 108, or one can secure theouter wheel 105, 106, 107, 108 and tap the output torque from the innerwheel 6.

FIG. 27 shows an exploded drawing of a further embodiment of a harmonicchain drive. Components similar to those shown in FIG. 26 have the samereference numerals. Instead of the chain slide 100 shown in FIG. 26,FIG. 27 has discs 109, 110 with a circular shape for dragging or liftingthe double chain 8′ into the outer wheel toothing 2. The discs 109, 110are mounted on ball bearings 111, 112 on shafts 113, 114 such that theyare able to rotate. The shafts 113, 114 are fitted to a dragger holder103 parallel to the axis of symmetry 10 and they are positioned oppositeone another in relation to the axis of symmetry 10 and they are locatedessentially at the same distance from the axis of symmetry 10.

FIG. 28 shows a cut-out from the double chain 8′ as used in theembodiment as shown in FIG. 26. The double chain 8′ is designed as aroller chain. In the double chain 8′, a bush 117 is surrounded by aroller 24. The two bushes 117 are connected together by two plates 25.Four outer plates 116 join two chain links. The four outer plates 116sit directly on the bolts 23.

Provided between a bush 117 and a roller 24 is a space into whichlubricant can be introduced. The rollers 24 are therefore able to rotatefreely on the bush 117. The use of a roller chain rather than a simplebush chain reduces the friction between dragger and chain as a result ofthe rotating rollers. Thus in the embodiment illustrated in FIG. 27 itis possible to dispense with the ball bearings 111, 112.

On the other hand, a chain without rollers, a bush chain or bolt chainfor example, can also be used if any slip between dragger and chain iscompensated for by ball bearings such as in the embodiment of FIG. 27.

As can be seen best in the embodiments of FIGS. 24, 25, and 27, it ispossible to design a region of the transmitter carrier as a toothed ornon-toothed eccentric disc which is mounted eccentrically in relation tothe axis of the output shaft to transmitting torque over the chain 8,8′, 8″ between the outer wheel toothing 2 and the inner wheel 6. In thisarrangement, the region of the toothing of the eccentric disc about thepoint furthest away from the axis of the output shaft 11 and theeccentric mounting of the eccentric disc corresponds to a transmitter asshown in the embodiments of FIGS. 1-15 or FIG. 26. The inner wheel 6 ispressed against the chain 8, 8′, 8″ by an eccentric movement of thetoothed eccentric disc, and the chain 8, 8′, 8″ is moved further by theeccentric movement of the eccentric disc. If the inner wheel 6 is movedin relation to the outer wheel, the chain 8, 8′, 8″ would engage thetransmitter and move the transmitter carrier 5 around its axis ofrotation.

When using an eccentric disc as a transmitter, it is possible to useballs or rollers—rather than a traction means—as pressure means to rollaround the rounded spaces between the teeth of the outer externaltoothing 2.

FIGS. 29 to 34 show a further embodiment of a motor-gear unit with adouble chain. In this embodiment the output shaft takes the form of anoutput ring 269. The eccentric discs 283, 291, eccentric cam bearings284, 288 and dragger discs 285, 287 form a transmitter.

FIG. 29 shows a partially-exploded drawing of the further embodiment ofa motor-gear unit. The gear parts of the motor-gear unit are omitted inFIG. 29; they are shown in FIG. 30 and are indicated by a number of dotsin FIG. 29. FIG. 29 shows, from left to right, a front housing section16, a motor block 270 with a partially-visible stator block 22 and arotor 5, a support cylinder 268 on which an output ring 269 isconcentrically mounted on a first output bearing 271 and a second outputbearing 272, and a bearing holder 18′.

Positioned concentrically inside the motor block 270 is a shaft 11 (notillustrated in FIGS. 29 and 30). Similar to the embodiment shown in FIG.18, this shaft 11 is fixed to a frame by a wishbone, which is also notshown here. The output ring 269 is connected to a rim flange in a mannersimilar to that shown in FIG. 18. Unlike in FIG. 18, however, the outputring 269 is mounted on a support cylinder 268 and not directly on therotor 5, as shown in FIG. 18. This increases stability and reducesfriction in comparison with the version shown in FIG. 18. In addition,in the version shown in FIG. 29 it is easier to use the same motordesign as is used when output is via the inner wheel.

The support cylinder 268 is designed as a hollow cylinder with a flange,the flange of the support cylinder 268 being screwed to a flange on themotor block 270. The output bearings 271, 272 are designed as annularball bearings which are positioned concentrically inside the output ring269, one on the motor side and one on the gear side.

Located between the gear-side output bearing 272 and the bearing holder18′ are gear parts which are shown in FIG. 30.

FIG. 30 shows an exploded drawing of the gear parts omitted in FIG. 29.FIG. 30 shows, from left to right, an annular outer wheel holder 275, anannular inner wheel 6, a double chain 8′, an outer wheel 276 consistingof the four identical ring sections 277, 278, 279, 280, an outer wheelholding ring 281, a disc-shaped eccentric cam holder 282, a motor-sideeccentric cam 283, a motor-side eccentric cam bearing 284, a motor-sidedragger ring 285, a gear-side dragger ring 287, a gear-side eccentriccam bearing 288, a spacer ring 290, a gear-side eccentric cam 291 and arim holder 18′, as shown in FIG. 29.

The outer wheel holder 275 is screwed firmly to a front face of therotor 5, which is shown in FIG. 29. The four ring components 277, 278,279, 280 of the outer wheel 276 are fixed between the outer wheelholding ring 281 and the outer wheel holder 275 via screw holes.

The outer wheel 276, the outer wheel holder ring 279 and the rim holder18′ are screwed via screw holes positioned one above the other to theouter wheel holder 275, which is in turn screwed firmly to the outputring 269.

The motor-side circular eccentric disc 283 is screwed fast eccentricallyto the disc-shaped eccentric cam holder 282 which is in turn screwedfast concentrically to the front face of the rotor 5. Located on theeccentric cam holder 282 is a disc-shaped projection on which is placedthe motor-side eccentric cam bearing 284. Positioned concentrically tothe centre point of the motor-side eccentric disc 283 on the outside ofthe motor-side eccentric disc 283 is the motor-side eccentric cambearing 284. Positioned concentrically to the centre point of themotor-side eccentric cam bearing 284 on the outside of the motor-sideeccentric cam bearing 284 is the motor-side dragger ring 285.

The gear-side circular eccentric disc 291 is screwed fast to themotor-side circular eccentric disc 283. Located between the eccentricdiscs 283 and 291 is spacer ring 290, which is placed on a disc-shapedprojection 286 of the motor-side eccentric cam 283. Positionedconcentrically to the centre point of the gear-side eccentric disc 291on the outside of the gear-side eccentric disc 291 is the gear-sideeccentric cam bearing 288. Positioned concentrically to the centre pointof the gear-side eccentric cam bearing 288 on the outside of thegear-side eccentric cam bearing 289 is the gear-side dragger ring 287.

In this arrangement the motor-side eccentric disc 283 and the gear-sideeccentric disc 291 are positioned in relation to one another such thatthe point on the eccentric disc 283 furthest away from the shaft 11 andthe point on the eccentric disc 291 furthest away from the shaft 11 areopposite one another in relation to the shaft 11. In addition, theeccentric cam holder 282, the motor-side eccentric cam 283 and thegear-side eccentric cam 291 are screwed to a front face of the rotor 5by four screws which pass through screw holes positioned one above theother. These screws are indicated schematically in FIG. 30. The twoidentical dragger rings 285 and 287 have an L-shaped profile as areshown particularly clearly in FIG. 32. It is therefore possible to makethe two identical eccentric cam bearings 284 and 288 and the twoeccentric discs 283 and 291 thicker than the width of the gear-sidechain 274 of the double chain 8′.

The inner wheel 6 is positioned in the axial plane of a motor-side chain273 of the double chain 8′, whereas the outer wheel 76 and the motor-and gear-side dragger rings 85, 87 are positioned in the axial plane ofa gear-side chain 274 of the double chain 8′. The radii of the draggerrings 285, 287 are dimensioned such that the gear-side chain 274 of thedouble chain 8′ engages in the outer wheel toothing 2 in two draggerregions in which the dragger rings 285, 287 lie adjacent to the doublechain 8′, the two dragger regions being substantially opposite oneanother in relation to the axis of symmetry of the shaft 11. Inaddition, the length of the double chain 8′ is dimensioned such that themotor-side chain 73 of the double chain 8′ engages in the inner wheel 6in two regions which are roughly opposite one another and which areapproximately 45 degrees distant from the dragger regions.

In the embodiment of FIGS. 29-34, the transmitter carrier and thetransmitter comprise the eccentric cam holder 282, the eccentric cam283, the eccentric cam bearing 284, the dragger ring 285, the draggerring 287, the gear-side eccentric cam bearing 288, the spacer ring 290,the gear-side eccentric cam 291 and the rim holder 18′. The transmitterscomprise the dragger ring 258 and the dragger ring 287, respectively.Furthermore, an outer wheel 276 with an outer wheel toothing 2 is givenby the four ring components 277, 278, 279, 280, 276.

FIG. 31 shows a view of the motor-gear unit of FIG. 29 as seen from thegear side. In this arrangement, the motor-side dragger ring 285, thegear-side dragger ring 287 and the gear-side eccentric cam bearing 288are visible through the holes in the rim holder 18′.

FIG. 32 shows a section through the motor-gear unit of FIG. 29 along theline of intersection marked K-K in FIG. 30 which runs through theopposing dragger regions. The two chain rows 273, 274 of the doublechain 8′ are shown in cross-section, one continuous chain bolt beingvisible on the left and another on the right. The inside of the draggerrings 285, 287 in opposing dragger regions lie adjacent to the gear-sidechain 274 of the double chain 8′. The motor-side chain 273 of the doublechain 8′ is lifted off the inner wheel in the plane of the line ofintersection K-K.

FIG. 33 shows a side view of the motor-gear unit of FIG. 29. In order toillustrate the internal structure of the motor-gear unit in FIG. 33 theline of intersection L-L is shown as angled.

FIG. 34 shows a further section through the motor-gear unit of FIG. 29along the line of intersection marked L-L in FIG. 33. The motor-sidedragger ring 285, the motor-side eccentric cam bearing 284 and thespacer ring 290 placed in front of it are shown in the front part of thesectional plane which runs through the gear-side chain 274 of the doublechain 8′. FIG. 34 shows that the radius of the spacer ring 290 isdimensioned such that it is larger than the smallest distance betweenthe motor-side eccentric cam bearing 284 and the axis of symmetry of theshaft 11.

A further part of the motor-side eccentric cam bearing 284 is shown inthe rear section of the cutting plane L-L which runs through themotor-side chain 273 of the double chain 8′. The inner wheel 6, adjacentto which lies the motor-side chain 273 in the lower region of FIG. 30,is also shown. Behind it can be seen part of the front face of therotors 5 in which ventilation holes are provided.

When the motor is in operation, the rotor 5 is set in rotation by theaction of a force on permanent magnets fitted to it. This causes theeccentric discs 283, 291 which are screwed to the rotor 5, to rotateabout the shaft 11. The rotation of the eccentric discs 283, 291 aboutthe shaft 11 is transmitted via the eccentric cam bearings 284, 288 tothe dragger discs 285, 287, which are positioned concentrically inrelation to the axis of symmetry of the eccentric cam 283, 291. Therotation of the dragger discs 285, 287 causes the dragger regions of thegear-side chain 274 to rotate about the axis of symmetry of the shaft 11as well. In the process the dragger discs 285, 287 rotate on theeccentric cam bearings 284, 288 and thereby deflects the lateral forceof the double chain onto the dragger discs 285, 287.

The double chain 8′ has fewer chain links than the number of teeth onthe outer wheel 276. In addition, the chains of the double chain 8′engage in the teeth in the inner wheel 6 and the outer wheel 276. Thedouble chain 8′ therefore has no slip in relation to them. As a resultthe outer wheel must progress nA−nK teeth, i.e. (nA−nK)/nA*360°, aroundthe shaft 11 for each revolution of the dragger discs, nA being thenumber of teeth on the outer wheel and nK being the number of chainlinks in the double chain 8′. This gives a speed reduction ratio ofnA/(nA−nK).

The outer wheel 276 transmits its rotational movement to the outer wheelholder 275, and to the output ring 269 to which it is connected by ascrew connection. The output ring 269 rotates on the output bearings 271and 271. The rotational movement of the output ring 269 is transmittedto a drive wheel of a vehicle. This can be achieved directly via a drivewheel rim flange fitted directly to the output ring 269 or indirectlyvia a chain drive in a manner similar to that shown in FIG. 18.

A motor-gear unit as shown in the embodiment illustrated in FIGS. 29 to34 offers a number of advantages. Since the distance between the draggerrings 285, 287 and the shaft 11 remains constant and the dragger rings285, 287 also largely fill the space inside the outer wheel, very littleimbalance is generated.

Due to the special arrangement of the dragger rings 285, 287 it ispossible to choose large dragger ring 285, 287 radii. This enables thedragger regions to be extended so that no sporadic loads occur. Inaddition it is also possible to achieve a higher speed reduction sincethe change length of the double chain 8′ can also be longer.

The mounting of the dragger rings 285, 287 on ball bearings 284, 288which are positioned a preset distance from the shaft 11 ensures that noor little slip occurs between the double chain 8′ and the outer wheeltoothing 2. Friction losses are also reduced. In addition it is notnecessary to use a roller chain to compensate for slip. A simple boltchain is sufficient. This also means that the design of the double chain8′ can be more stable.

Further advantages of the embodiment with the double chain asillustrated in FIGS. 29 to 34 have already been detailed in relation tothe embodiments shown in FIGS. 23 to 27 with the double/triple chain.The same or similar advantages apply here.

In the embodiment illustrated in FIGS. 29 to 34, it is possible to use adouble roller chain instead of, or in addition to, the eccentric cambearing 284, 288.

In a version of the embodiment illustrated in FIGS. 29 to 34 the outputcan also be via the inner wheel 6. To this end, the dragger discs 285,287 and the outer wheel 276 are provided in the motor-side chain plane273 and the outer wheel 276 is fixed to a stationary part of thehousing. The inner wheel 6, on the other hand, is provided in thegear-side chain plane 274 and the inner wheel 6 is fixed to an outputring 269.

In this arrangement the radius of the output ring 269 is usefully largerthan the radius of the outer wheel 276. In this context, the term ‘fix’is taken to include indirect fixing using intermediate parts.

In the case of both output via the outer wheel 276 and output via theinner wheel 6 it is also possible to transmit the rotational movementinwards to an output shaft 11, instead of outwards to an output ring269, in which case both the output ring 269 and the output bearings 271,272 are omitted. The inner wheel 6 and the outer wheel 276 can then befixed to the output shaft 11, and the output shaft 11 can be supportedon ball bearings in a manner similar to that illustrated in FIG. 2 forthe inner wheel 6.

FIG. 35 shows a version of the previous embodiments having a pushingmeans or pressure means. A pressure means 131 is provided between arotating inner wheel 6 and a stationary outer wheel 130 in place of atraction means. The pressure means 131 may for example take the form ofa flexible metal ring or metal cylinder. The pressure means 131, theinner wheel 6 and the outer wheel 130 are shaped such that there islittle or no slip between the pressure means 131 and the inner wheel 6and between the pressure means 131 and the outer wheel 130. This shapingmay take the form of teeth, for example.

Two pressure wheels 132, 133 are positioned on a rotating carrier ring134 in such a manner that they are positioned before the pressure means13 in the direction of movement of the carrier ring and make contactwith the pressure means 131. In this arrangement the carrier ring andthe pressure wheels 132, 133 correspond to a transmitter located betweenthe inner wheel 6 and the outer wheel 130. To reinforce the pressuremeans 131 it is also possible to optionally provide stabilising wheels135, 136 which work against the pressure wheels 132, 133 adjacent to thepressure means. As a further option it is also possible to provide as acomponent of the transmitter two further pressure wheels (notillustrated) in order to push the pressure means against the inner wheelfrom the outside. The pressure wheels or stabilising wheels arepositioned such that they are able to rotate about their axis and thepressure means 131 are able to revolve. The revolving pressure means 131transmits its revolving movement to the inner wheel 6.

In the version illustrated in FIG. 35 it is also possible for the innerwheel to be stationary and output to be via the outer wheel 130. In thiscase input and output both have the same direction of rotation.

FIGS. 36 to 46 show further embodiments wherein parts which are alreadymentioned above are not in explained in further detail.

FIG. 36 shows an exploded view of an embodiment with a two-pin-row pinring 308. To the right of the second output bearing 272 FIG. 35 shows,from left to right, a first inner ring 6′, a two-pin-row pin ring 308, amotor side dragger disk 285′ with motor side eccentric cam 283′ andmotor-side eccentric cam bearing 284′, a gear side dragger disk 287′with a gear-side eccentric cam 291′ and a gear-side eccentric cambearing 288′, a second inner ring 6″ as well as parts shown in previousembodiments. The dragger disks 285′ and 287′ are shaped as circulardisks.

This is a three row gear design wherein the two pairs 6′, 2′respectively 6″, 2″ of an inner wheel and an outer wheel are located indifferent axial planes, wherein the transmitter carrier withtransmitters 285′, 287′, 283′, 284′, 288′, 291′ is located in a thirdaxial plane between the two pairs 6′, 2′ respectively 6″, 2″ of an innerwheel and an outer wheel.

The first inner ring 6′ and the second inner ring 6″ are connected tothe stator 22. An outer wheel toothing 2′, 2″ is designed as a two rowinner toothing of an output ring 269.

Here, the two pin rows of the pin ring 308 as a traction means extendbetween the inner peripheries 2′, 2″ of the outer wheels and the outerperipheries 7′, 7″ of the inner wheels 6′, 6″. The protruding parts ofthe pins 305 which can be best seen in FIG. 46 provide the function ofthe bolts of a traction chain that interact with the teeth of the outerwheels and inner wheels 6′, 6″. In the case of a driven transmitter285′, 287′, 283′, 284′, 288′, 291′, the pin ring 308 is lifted off theouter peripheries 7′, 7″ of the inner wheels 6′, 6″ and pushed againstthe inner peripheries 2′, 2″ of the outer wheels, thereby creating arelative movement between the inner wheels and the outer wheels. Incases, where the inner wheels 6′, 6″ are driven, a relative movementbetween the outer wheels and the pin ring 308—and thereby thetransmitter 285′, 287′, 283′, 284′, 288′, 291′—is provided. In stillother cases, where the outer wheel is driven, a relative movementbetween the inner wheel 6′, 6″ and the pin ring 308—and thereby thetransmitter 285′, 287′, 283′, 284′, 288′, 291′—is provided. Thetransmitter 285′, 287′, 283′, 284′, 288′, 291′ is then driven by the pinring 308.

The output ring 269 is rigidly connected to an output drive such as arim flange.

On the motor-side eccentric cam 283′ four adjustment slits 301 areprovided, which are oriented at a right angle to a radius of themotor-side eccentric cam 283′. The four adjustment slits 301 comprisetwo pairs of adjustments slits. The adjustment slits 301 of each pairhave the same orientation and the adjustments slits 301 of the pairs areoriented perpendicular to each other. Guiding cylinders are provided inthe adjustment slits, which can be seen in FIG. 47. Holes in the gearside eccentric cam 291′ are shaped as oblong holes.

Via the adjustment slits 301, the eccentricity of the dragger 285′ and287′ can be adjusted by shifting the eccentric cams 283′, 291′ andthereby the dragger disks 285′ and 287′ along the adjustments slits 301.Thereby, the two-pin-row pin ring 308 is tightened. When the center ofthe gear side eccentric cam 291′ is moved away from the symmetry axis 10along two of the guiding cylinders, the pin ring 308 is tightened. Theoblong holes of the gear-side eccentric cam 291′ allow movement of thegear-side eccentric cam 291′ relative to screws which pass through theoblong holes.

When the gear side eccentric cam is tightened to the motor sideeccentric cam via the screws, which pass through the oblong holes of thegear side eccentric cam 291′ and through corresponding holes of themotor side eccentric cam 283′, the gear side eccentric cam 291′ ispressed against the guiding cylinders and against the motor sideeccentric cam 291′, and the position of the gear side eccentric cam 291′is fixed.

FIG. 37 shows a cross section through the motor-gear unit of FIG. 36.

FIGS. 38 and 39 show an exploded view of two embodiments of a harmonicchain drive with a two sided pin ring 308 and a wire race bearing 302.In contrast to the embodiment of FIG. 36, the dragger disks 285″ and287″ are not designed as circular dragger disks but as oval shapeddragger disks. Preferentially, the center of the ovals lies on thesymmetry axis 11 such that the oval shaped disks lie on top of eachother. The eccentric cams 283′, 291′ shown in FIG. 36 are not used inthe embodiment of FIG. 38. Also, the eccentric cam bearings are not usedhere. Instead, the friction is taken up by the wire race bearing 302,303 also known as “Franke bearing”. The wire race bearing 302, 303 isarranged between the dragger disks 285″, 287″ and the output ring 269.Through the revolving movement of the dragger disks 285″, 287″ the wirerace bearing 302, 303 is deformed and is pressed against the outer wheeltoothing 2. During operation, the wire race bearing 302, 303 takes upthe friction between the dragger disks 285″, 287″ and the inner surfaceof the two-pin-row pin ring 308, which can be best seen in FIG. 46.

FIGS. 38 and 39 differ in the type of wire race bearing 302, 303. InFIG. 38 a complete wire race bearing 302 is used, comprising four wirerings and a flexible ball cage. The four wire rings are arranged suchthat they enclose the balls of the ball bearing. The balls are held inthe flexible ball cage. The four wire rings can be seen in the crosssectional view of FIG. 43. In alternative embodiments, the number of thewire rings may also be two, three or more than four. In FIG. 39, aninner part 303 of a wire race bearing is used, comprising a flexibleball cage but no wire rings.

FIG. 40 shows a cross sectional view through a motor gear unit accordingto FIG. 38 or FIG. 39. A slit is provided between the inner wheeltoothing and the outer wheel toothing such that the slit is just largeenough to take up the pins 305. The smaller the slit, the larger thetransmission ratio for a given tooth size of the toothings. As a result,particularly large transmission ratios are possible for the embodimentswith a pin ring 308.

FIG. 41 shows a cross section through the motor gear unit according toFIG. 36. The cross section is taken in a plane that passes through theopposing dragger regions, from which one dragger region is shown. It canbe seen that the motor side dragger ring 285′ pushes against a flexiblering 304 of the pin ring 308 such that the pin 305 pushes against anouter wheel. The outer wheel is designed as two outer wheels which arerealized as inner toothings of the bearing support 18 and the outputring 269, which are rigidly connected with screws. The toothings are notshown here, but in FIG. 36. The eccentric cams on which the draggerrings 285′, 287′ are supported via bearings are screwed to the rotor 5via four screws from which on screw end is visible in FIG. 42.

FIG. 46 shows a detailed view of the two-pin-row pin ring 308. The twopin rows of the two-pin-row pin ring 308 are formed by steel made pins305 of width 20 mm and thickness 1.5 mm which are protruding from bothsides of the central elastic ring 304. The elastic ring 304 ispreferentially made from metal, such as iron, aluminium, bronze or otheralloys. The elastic ring 304 comprises elongated gaps in which the pins305 may be fitted.

FIG. 42 shows a cross sectional view through the motor gear unitaccording to FIG. 37. The cross section is similar to the cross sectionof FIG. 41. But in contrast to FIG. 41, the flexible ring is pushedoutside not by two slightly axially asymmetric dragger discs but by theballs of the bearing that are located in the middle plane of theflexible ring element 304 of the traction means or pin ring such thatthe balls follow a circular path on the inner surface of the pin ring308. It can further be seen that balls of an inner part of a wire racebearing are supported in a round groove of the oval dragger disks 285″,287″, so as to guide the balls from the inner side. A flexible cage ofthe inner part of the wire race bearing is shown in cross section. Onthe inside of the flexible ring 304, a round groove is provided as well,so as to guide the balls from the outer side. Through the use of thecircular grooves it is no longer necessary to provide ring wires toguide the balls but a flexible cage with balls is sufficient, such asprovided by an inner part of a wire race bearing.

FIG. 43 shows a cross sectional view through the motor gear unitaccording to FIG. 38. In contrast to the previous FIG. 42, a full wirerace bearing is provided. The four wires can be seen in the outercorners of a square-shaped gap, which is bound by a rectangular openingof the dragger disks 285″, 287″. and a rectangular opening on a part onthe inside of the flexible ring 304 of the pin ring 308. The four wiresare supported by the rectangular opening. A ball cage is shown incross-section on each side of the ball.

FIG. 44 shows a partial cross section through the motor gear unitaccording to FIG. 37. From the inside to the outside, an oval draggerdisk 287′, the wire race bearing 302 and the two-pin-row pin ring 308are shown. A ball cage and wire rings of the race ball bearing 302 areshown from the side. In an enlarged section, the ball cage is shown fromthe side.

FIGS. 45 and 46 show detailed views of the two-pin-row pin ring 302. Inthis view, an inner and an outer border of an elastic ring 304 areshown, in which pins 305 are provided with a diameter of 1.5 mm. Thedistance from the inner to the outer ring is 3 mm and the radius of theundeformed race ball bearing is 205 mm. An advantage of the race ballbearing 302 in the abovementioned embodiments is its deformability bythe pressure of the dragger disks 285′, 285″, 287′, 287″.

In the embodiments of FIGS. 36-46, which comprise a pin ring 302, atransmitter carrier with transmitters which is arranged inside the pinring 302, revolves around the axis 10. The transmitters push against theflexible inner ring of the pin ring 302 and, in two opposing draggerregions, lift the pins of the pin ring from the inner wheel/wheels. Inthe dragger regions, the pins 305 of the pin row are pushed between theteeth of the outer wheel toothing/toothings. The pins 305 in turn exerta lateral force against the outer wheel toothing/toothings such that theouter wheel turns.

In the embodiments, the transmitters are realized as circular or ovalshaped dragger disks or dragger rings and the transmitter carriers arerealized as a support on which the transmitter are fixed. A bearingwhich takes up the friction can be seen as part of the transmitter forthose embodiments which provide a flexible bearing between the draggerdisks and the outer wheel toothing and as part of the transmittercarrier in the embodiments in which the dragger disks are supported onthe bearing from the inside.

FIG. 47 shows a further embodiment in which a tooth belt 310 is used aspressure means.

To the right of the second output bearing 272 FIG. 35 shows, from leftto right, an outer wheel 276′, a first inner ring 6′, a tooth belt 310,a motor side dragger disk 285′ with motor side eccentric cam 283′ andmotor-side eccentric cam bearing 284′, a gear side dragger disk 287′with a gear-side eccentric cam 291′ and a gear-side eccentric cambearing 288′, as well as parts shown in previous embodiments. Thedragger disks 285′ and 287′ are shaped as circular disks.

This design corresponds to a two row gear design wherein the the innerwheel 6 and the dragger disks 285′, 287′ are located in two differentaxial planes. The outer wheel 276′ extends over the whole width of thetooth belt 310, in contrast to the previous embodiments comprising atwo-pin-row pin ring. The inner ring 6 is connected to the stator 22. Anouter wheel toothing 2 is designed as inner toothing of an outer ring276′.

The tooth belt 310 as a traction means extends between the innerperiphery 2 of the outer wheel 276′ and the outer periphery of the innerwheel 6. The teeth of the tooth belt 310, which is designed as a toothbelt with inner and outer toothing, have the function of the bolts of atraction chain that interact with the teeth of the outer wheel 276′ andthe inner wheels 6. In the case of a driven transmitter 285′, 287′,283′, 284′, 288′, 291′, the tooth belt 310 is lifted off the outerperiphery 7 of the inner wheels 6 and pushed against the innerperipheries 2 of the outer wheel 276′, thereby creating a relativemovement between the inner wheels and the outer wheels. In cases wherethe inner wheel 6 is driven, a relative movement between the outer wheel276′ and the tooth belt—and thereby the transmitter 285′, 287′, 283′,284′, 288′, 291′—is provided. In still other cases, where the outerwheel is driven, a relative movement between the inner wheel 6 and thetooth belt—and thereby the transmitter 285′, 287′, 283′, 284′, 288′,291′—is provided. The transmitter 285′, 287′, 283′, 284′, 288′, 291′ isthen driven by the tooth belt.

The output ring 269 is rigidly connected to an output drive such as arim flange.

On the motor-side eccentric cam 283′ four adjustment slits 301 areprovided, which are oriented at a right angle to a radius of themotor-side eccentric cam 283′. Guiding cylinders are provided in theadjustment slits 301. Holes, that are provided in the gear sideeccentric cam 291′, are shaped as oblong holes. The mechanism ofadjustment and tightening of the tooth rim is analogous to the previousdescription with reference to FIG. 36.

FIG. 48 shows a cross section through the harmonic chain gear of FIG. 47along an angled plane, such that half of the plane cuts in front of theinner wheel 6 and the other half cuts in front of the motor-side draggerdisk 285′. The position of the dragger disks 285′ and 287′ is such thatthe two opposing dragger regions lie at the border of the two halves ofthe cross section. It can be seen that the adjustment slit is in thedirection of a line which connects the dragging regions.

FIG. 49 shows a cross section through the harmonic chain gear of FIG.47, wherein the cutting plane runs through the symmetry axis 10 and theopposing dragger regions. Part of the tooth belt 310 is shown in thedragger regions. Two of the four screws with which the eccentric camsare fixed to the rotor 5 are seen in cross section, as are two of thesix screws with which the inner wheel 6 is fixed to the stator 22.

For the embodiments which are shown or described in this application, itis in principle possible to use all types of electric motors togetherwith the harmonic chain drive gear. Brushless DC motors in which therotor is provided with permanent magnets can be simple and at the sametime advantageous in this arrangement. To this end the stator has coilwindings, as shown in the embodiments, to which a suitably pulsed directvoltage is applied, and generates an alternating magnetic field whichcooperates with the permanent magnets which in turn causes the rotor torotate. In this arrangement it is possible to provide sensors in theregion of the rotor in the form of auxiliary coils or Hall sensors todetermine the momentary position of the rotor taken into account incontrolling the current through the coil windings.

Sensor-less motor designs are also conceivable in which the currentrotor position is determined by an induction voltage in a coil or coilsof the stator.

In further versions it is possible to use synchronous motors orasynchronous motors together with the harmonic chain drive gear asdisclosed in the application. In such cases they are often referred toas AC motors. Asynchronous motors have the advantage that they can beoperated without brushes because a rotating electromagnetic fieldentrains the rotor which is designed as a short-circuit winding in whichthe alternating field induces a magnetic field.

Alternatively it is also possible to use DC motors in which brushes areused to apply current to the rotor coil.

The coils in the rotor and the stator of synchronous motors and DCmotors can be operated in series or in parallel. In principle allcombinations are conceivable, i.e. synchronous series motors,synchronous parallel or shunt motors, DC series motors and DC parallelor shunt motors. Synchronous motors can also be fitted with a permanentmagnet as the rotor, in which case a combination with a rotor coil isalso conceivable.

Synchronous motors which can be operated in parallel have a torque curvewhich is largely constant in relation to speed. Conversely, theavailable torque of a synchronous motor operated in series rises asspeed increases.

With asynchronous motors and also with synchronous parallel motors atipping point is observed at which a maximum torque is reached. When thespeed falls below a certain level, the available torque decreases. Inrotary-current motors in particular angle of rotation has no particularinfluence on stationary torque.

In motors with series connection behaviour a stronger fall in speed canbe observed under load. Motors with series connection behaviour aretherefore particularly suitable for the subject matter of theapplication because operating without switchgear, i.e. with a fixedspeed reduction, is possible over a wide speed range.

Here DC series motors which develop a very high speed at low load, butin which the speed then drops sharply as load increases, have provedparticularly successful. They produce a high-speed drive with highstarting torque which is particularly desirable when driving vehicles.When starting from stationary a series motor and in particular a DCseries motor has a high torque which permits high starting acceleration.The speed can reach very high levels entirely without load. Anelectronic control unit advantageously counters this by reducing powerthrough the application of a lower drive voltage to the motor.

With appropriate switching to control the coils of the stator of anasynchronous motor it is possible to generate similar properties, thereis also the advantage that no collector and no brushes are required todrive the rotor. In fact, this results in a more robust short-circuitrotor of simple design which has a characteristic curve similar to thatof the series motor.

In terms of the structural design of the electric motor, both double andsingle split axial motors are possible. A radial motor with an innerrotor or an outer rotor is also conceivable. Outer rotors have theadvantage of a higher moment of inertia which has a favourable effect onthe running smoothness of the drive unit it forms. Combinations of axialmotors and radial motors are also conceivable, in particular when theyare designed as outer rotors.

The subject matter of the application can be realised with a wide rangeof electric motor types including AC motors, DC motors, brushless DCmotors, series-wound motors, shunt-wound motors, synchronous motors andasynchronous motors. Internal combustion engines such as piston enginesor even combustion turbines can also be used.

The above mentioned types of electric motors can in principle also beused as a generator, wherein the part of the gear that is connected withthe main shaft of the motor is the output shaft of the gear.

The gear can also be employed to use a slow-speed drive unit such as awater turbine or wind turbine, to drive a generator at a relatively highspeed.

Alternatively, the gear can also be employed to use a high-speed driveunit such as an internal combustion engine or a gas or fuel combustionturbine to drive a generator at a relatively low speed.

The embodiments of the application which have been described above havein principle in common an outer wheel and an inner wheel, whereby atraction means extends between the inner periphery of the outer wheeland the outer periphery of the inner wheel. Commonly used traction meansinclude plastic or metal chains, toothed belts and deformable metal orplastic cylinders or other elliptic shapes. In the case of a driventransmitter, the traction means is lifted off the outer periphery of theinner wheel and pushed against the inner periphery of the outer wheel,thereby creating a relative movement between the inner wheel and theouter wheel. In cases where the inner wheel is driven, a relativemovement between the outer wheel and the traction means—and thereby thetransmitter—is provided. In still other cases, where the outer wheel isdriven, a relative movement between the inner wheel and the tractionmeans—and thereby the transmitter—is provided. The transmitter is thendriven by the traction means.

The application also covers a further embodiment in which a pressuremeans or pushing means for transmitting mainly compression forces isprovided in place of a traction means which transmits mainly tensileforces between the inner wheel and the outer wheel. Metal or plasticcylinders or other elliptic shapes are often used as a pressure means.Such a gear then has an input shaft and an output shaft, the gear havingan outer wheel, an inner wheel arranged concentrically in relation tothe outer wheel and the pressure means extending between the outer wheeland the inner wheel, and at least one revolving transmitter which urgesor pushes the pressure means away from the inner periphery of the outerwheel and towards the outer periphery of the inner wheel. In the case ofa driven transmitter, the pressure means is pushed off the outerperiphery of the inner wheel and pushed against the inner periphery ofthe outer wheel, thereby creating a relative movement between the innerwheel and the outer wheel. In cases, where the inner wheel is driven, arelative movement between the outer wheel and the traction means—andthereby the transmitter—is provided. In still other cases, where theouter wheel is driven, a relative movement between the inner wheel andthe pressure means—and thereby the transmitter—is provided. Thetransmitter is then driven by the pressure means.

The pressure means may be designed as a flexible metal sheath which isable to transmit thrust forces and bending moments. Where this is thecase the transmitters lie against the outside of the sheath and drag itfrom tooth to tooth. The subject matter of the application also relatesto a harmonic chain gear in which the transmitters are mounted on shaftssuch that they are able to rotate and the shafts are provided on thetransmitter carrier. In this arrangement, the transmitters may bedesigned as gear wheels or rollers.

In an axially asymmetric one row gear design such as in the embodimentsof FIGS. 1-22 and in FIG. 35, the traction means respectively thepressure means has one single radial section that is provided both forthe contact with the outer wheel and for the inner wheel. In the one rowgear design, the transmitter generally contacts the traction meansrespectively the pressure means from within the gap between the innerwheel and the outer wheel. The transmitter, the inner wheel, the outerwheel as well as the traction means respectively the pressure means arelocated essentially in the same axial plane.

In an axially asymmetric two row gear design such as in the embodimentsof FIG. 23, FIGS. 26-34, and FIGS. 47-49, the inner wheel and the outerwheel are often located in different axial planes, wherein thetransmitter is either located in the axial plane of the inner wheel orin the axial plane of the outer wheel. The traction means respectivelythe pressure means extends axially between the axial planes of the innerwheel and the outer wheel, contacting both the inner wheel and the outerwheel at different sections of their respective circumferences.

In a three row gear design such as in the embodiments of FIGS. 36-46,the two pairs of an inner wheel and an outer wheel are located indifferent axial planes, wherein the transmitter is located in a thirdaxial plane between the two pairs of an inner wheel and an outer wheel.

In a further embodiment which is not shown in the Figures, a three rowgear design is provided with two inner wheels and one outer wheelor—alternatively—also with two outer wheels and one inner wheel.

It is also possible to provide a three row gear design with one innerwheel and one outer wheel. As shown in FIGS. 24-25, it is then alsopossible to provide a double row transmitter with two transmittersections, wherein each transmitter section is provided in an axial planewhich is different from the axial plane of the inner wheel. The tractionmeans respectively the pressure means extends axially between the axialplanes of the outer wheels and the inner wheel, contacting both theinner wheel and the outer wheels at different sections of theirrespective circumferences.

It is also possible, despite not being shown in the Figures, to providean axially symmetric three row gear design with two outer wheels and oneinner wheel, that are located in different axial planes, wherein thetransmitter is located in the axial plane of the inner wheel. It is thenalso possible to provide a double row transmitter with two transmittersections, wherein each transmitter section is provided in the axialplane of each outer wheel. The traction means respectively the pressuremeans extends axially between the axial planes of the inner wheels andthe outer wheel, contacting both the inner wheels and the outer wheel atdifferent sections of their respective circumferences.

In short, combinations of any number of inner wheels and any number ofouter wheels are possible, wherein a single row transmitter or amultiple row transmitter with multiple transmitter sections can be used.The embodiments show only some of the many combinations that aredisclosed in the present application.

That which is claimed is:
 1. A gear having an input shaft and an outputshaft, the gear comprising the following elements: an outer wheel; aninner wheel which is positioned concentrically in relation to the outerwheel; a traction means extending between the outer wheel and the innerwheel; and a revolving transmitter which lifts the traction means froman outer periphery of the inner wheel and pushes the traction means ontoan inner periphery of the outer wheel, the transmitter comprising afirst transmitter element and a second transmitter element provided on arotatable transmitter carrier, wherein the first transmitter element andthe second transmitter element are rotatable on the transmitter carrierand wherein each transmitter element is provided eccentrically from arotation axis of the transmitter carrier, the first transmitter elementcomprising a first disk, the first disk being supported on thetransmitter carrier by a first ball bearing, the second transmitterelement comprising a second disk, and the second disk being supported onthe transmitter carrier by a second ball bearing.
 2. The gear accordingto claim 1, wherein the traction means comprises a flexible splineelement, the flexible spline element comprising a multitude of pins thatstand proud of at least one axial surface of the spline element and thatare coaxially arranged with the spline element.
 3. The gear according toclaim 1, characterized in that the input shaft is connected to thetransmitter.
 4. The gear according to claim 1, characterized in that theinput shaft is connected to the outer wheel.
 5. The gear according toclaim 1, characterized in that the input shaft is connected to the innerwheel.
 6. The gear according to claim 1, characterized in that theoutput shaft is connected to the inner wheel.
 7. The gear according toclaim 1, characterized in that the output shaft is connected to thetransmitter.
 8. The gear according to claim 1, characterized in that theoutput shaft is connected to the outer wheel.
 9. The gear according toclaim 1, characterized in that the traction means is provided as a chainof rotatably interconnected links.
 10. The gear according to claim 1,characterized in that the traction means comprises at least onecontinuous elliptic traction element.
 11. The gear according to claim10, characterized in that the traction element comprises a flexiblebelt.
 12. The gear according to claim 1, characterized in that thetransmitter is positioned on the rotatable transmitter carrier.
 13. Thegear according to claim 12, characterized in that the transmitter isfixed to the transmitter carrier wherein the traction means comprises amultitude of rotatable contact elements.
 14. The gear according to claim12, characterized in that the transmitter is rotatably provided on thetransmitter carrier.
 15. A motor-gear unit with the gear according toclaim 1, characterized in that an electric motor is provided, a rotor ofthe electric motor being connected to the input shaft of the gear. 16.The motor-gear unit according to claim 15, characterized in that theelectric motor is a DC brushless motor with a radial gap.
 17. Amotor-gear unit with the gear according to claim 1, characterized inthat an internal combustion engine is provided, an output shaft of theengine being connected to the input shaft of the gear.
 18. A vehiclehaving the motor-gear unit in accordance with claim 15, characterized inthat at least one driven wheel of the vehicle is connected to the outputshaft of the gear.
 19. An electric generator with a drive unit and witha generator unit and with a gear according to claim 1, an input shaft ofthe gear being connected to the drive unit and an output shaft of thegear being connected to an input shaft of the generator.